Danger of replacing M96 engine in 2002 Coupe
#1
Instructor
Thread Starter
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Need to get opinions/advice on a project. 2002 996 Coupe with Tip, 120k miles and 2003 replacement engine. Car is is really good condition, except for installed engine. Cost for both(car and extra engine) is under $10,000.
Installed engine has "smoke", when it reaches operating temperature, but nothing at startup and no noise. AOS has been replaced, but no change in discharge.
Car ar comes with replacement engine with 70k miles. Plan is to replace the engine, with the engine that comes with the car that has 70k miles on it.
I can do the labor part, that doesn't bother me. What I want to know are what are the possible reasons for the smoke (oil or water), and if that is the cause, what steps would I need to take to mitigate the impact once engine is removed? For example hose replacement (what hoses)?, oil cooler and so on.
There doesn't appear to be water in the oil.
I know this is a wide open topic, and there could be several reasons for what is going on, but is there anything that should scare me off from a cost standpoint, or cause this project to head south with no chance of success?
Installed engine has "smoke", when it reaches operating temperature, but nothing at startup and no noise. AOS has been replaced, but no change in discharge.
Car ar comes with replacement engine with 70k miles. Plan is to replace the engine, with the engine that comes with the car that has 70k miles on it.
I can do the labor part, that doesn't bother me. What I want to know are what are the possible reasons for the smoke (oil or water), and if that is the cause, what steps would I need to take to mitigate the impact once engine is removed? For example hose replacement (what hoses)?, oil cooler and so on.
There doesn't appear to be water in the oil.
I know this is a wide open topic, and there could be several reasons for what is going on, but is there anything that should scare me off from a cost standpoint, or cause this project to head south with no chance of success?
#2
Rennlist Member
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Buy it
send it to flat six for 3.8L upgraded motor and address all the 28 known failure modes
your will be into it for 35-40k and have a great car worth 20k
Great fun car
send it to flat six for 3.8L upgraded motor and address all the 28 known failure modes
your will be into it for 35-40k and have a great car worth 20k
Great fun car
#4
Three Wheelin'
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Reasons for smoke are numerous. Bore scoring, worn valve seals, residual oil from AOS going back still in the intake manifold.
You have no guarantees about the 2nd engine either. Short of following 996AEs line and sending the engine to be "fortified" by Jake, you are still gambling with same issues on the replacement motor. The health of the replacement motor is not guaranteed either.
You are gambling on the deal. If 2nd motor is no good, you have a roller to sell.
Any details on the car? What color is it? VIN #?
You have no guarantees about the 2nd engine either. Short of following 996AEs line and sending the engine to be "fortified" by Jake, you are still gambling with same issues on the replacement motor. The health of the replacement motor is not guaranteed either.
You are gambling on the deal. If 2nd motor is no good, you have a roller to sell.
Any details on the car? What color is it? VIN #?
#5
Instructor
Thread Starter
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Oh..good call. I forgot to mention. The replacement engine was pulled from a running 911, and verified via video, before the engine was pulled. Naturally, this doesn't guarantee anything not going wrong in the future.
#6
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Buy the whole shebang, sell the car with the smoky engine for $10k, sell the known good engine with video for another $10k, then take the $20k and buy a coupe with a stickshift and service records and well under 100k miles for less than $20k. All done and no need to even wash your hands.
#7
Rennlist Member
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Need to get opinions/advice on a project. 2002 996 Coupe with Tip, 120k miles and 2003 replacement engine. Car is is really good condition, except for installed engine. Cost for both(car and extra engine) is under $10,000.
Installed engine has "smoke", when it reaches operating temperature, but nothing at startup and no noise. AOS has been replaced, but no change in discharge.
Car ar comes with replacement engine with 70k miles. Plan is to replace the engine, with the engine that comes with the car that has 70k miles on it.
I can do the labor part, that doesn't bother me. What I want to know are what are the possible reasons for the smoke (oil or water), and if that is the cause, what steps would I need to take to mitigate the impact once engine is removed? For example hose replacement (what hoses)?, oil cooler and so on.
There doesn't appear to be water in the oil.
I know this is a wide open topic, and there could be several reasons for what is going on, but is there anything that should scare me off from a cost standpoint, or cause this project to head south with no chance of success?
Installed engine has "smoke", when it reaches operating temperature, but nothing at startup and no noise. AOS has been replaced, but no change in discharge.
Car ar comes with replacement engine with 70k miles. Plan is to replace the engine, with the engine that comes with the car that has 70k miles on it.
I can do the labor part, that doesn't bother me. What I want to know are what are the possible reasons for the smoke (oil or water), and if that is the cause, what steps would I need to take to mitigate the impact once engine is removed? For example hose replacement (what hoses)?, oil cooler and so on.
There doesn't appear to be water in the oil.
I know this is a wide open topic, and there could be several reasons for what is going on, but is there anything that should scare me off from a cost standpoint, or cause this project to head south with no chance of success?
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#8
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If you have time to put labour into it and enough space to do so, it seems like a low risk way to spend $10k.
996 rollers are $7-8k on their own these days, so having one potentially bad and one potentially good motor for a bit more seems like a solid deal.
996 rollers are $7-8k on their own these days, so having one potentially bad and one potentially good motor for a bit more seems like a solid deal.
#9
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If you want a winter project, have the time, space, tools, and mechanical aptitude, then go for it. Otherwise, Walter's suggestion sounds like a great idea.
#10
Rennlist Member
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Walter's suggestion sounds like a solid "no risk" profit solution. Only thing I will add is on the smoking engine, the possible faults mentioned (bore score,valve seals, AOS) 1. bore score will usually smoke from one side, and usually accompanied by a light tapping noise 2. I have not seen any valve seals fail causing smoke on a m/96 engine 3.AOS failing is VERY likely and common 4. only other thing I can think of would be scavenge pump failure, if the scavenge pump drive breaks off the head will fill with oil and can cause oil to enter the AOS and/or leak past the valve seals. Checking the scavenge pumps is very easy. IF you were able to fix the smoking on the original engine , you will have hit a GRAND SLAM !
#11
Instructor
Thread Starter
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Buy the whole shebang, sell the car with the smoky engine for $10k, sell the known good engine with video for another $10k, then take the $20k and buy a coupe with a stickshift and service records and well under 100k miles for less than $20k. All done and no need to even wash your hands.
#12
Instructor
Thread Starter
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Walter's suggestion sounds like a solid "no risk" profit solution. Only thing I will add is on the smoking engine, the possible faults mentioned (bore score,valve seals, AOS) 1. bore score will usually smoke from one side, and usually accompanied by a light tapping noise 2. I have not seen any valve seals fail causing smoke on a m/96 engine 3.AOS failing is VERY likely and common 4. only other thing I can think of would be scavenge pump failure, if the scavenge pump drive breaks off the head will fill with oil and can cause oil to enter the AOS and/or leak past the valve seals. Checking the scavenge pumps is very easy. IF you were able to fix the smoking on the original engine , you will have hit a GRAND SLAM !
Good stuff. Thanks!
#13
Instructor
Thread Starter
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Ok. Little more info in current engine. Blue smoke out of passenger side exhaust (from left bank). No smoke at startup, but ONLY after warming up to operating temperature.
Most at all issue that I have read, with the engine and smoke, point to smoke at startup and then stop or there is noise associated with the issue.
Any thoughts on what might cause this only AFTER getting to temp?
Most at all issue that I have read, with the engine and smoke, point to smoke at startup and then stop or there is noise associated with the issue.
Any thoughts on what might cause this only AFTER getting to temp?
#14
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Hard to say without seeing the engine and performing some diagnosis.
For 10K buy the package. You will more then pay for your labor by selling off the worn out motor as a core. Then you have a car you are into for less than 10K. Have some fun with it, sell it, part it out? No matter what, your 10K is well protected.
If you want to sell the smokey engine, let me know. We may be interested in it .
Cheers
For 10K buy the package. You will more then pay for your labor by selling off the worn out motor as a core. Then you have a car you are into for less than 10K. Have some fun with it, sell it, part it out? No matter what, your 10K is well protected.
If you want to sell the smokey engine, let me know. We may be interested in it .
Cheers
#15
Rennlist Member
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Check the scavenge pump on bank 1, also check the AOS also located on bank 1, check compression and leakdown. Make a video and post it. I had a 996 years ago the had started smoking out of passenger side after hot. Customer stated the car had sat in the garage several months for winter storage. Finally found that a chip monk had stored dog food in the exhaust ! I'M SERIOUS !!